I can never keep the Martian seasons straight - is it almost a year till the sun rises again and we can see the ice buildup?

The press-release image, Declining sunlight for Phoenix lander graphs over a few Earth years, showing the hours of sunlight, and noting Phoenix-mission sol numbers, and a few earth dates.

First sunlight looks to come about mission sol 400, middle of the ice encasement. I don't know when there'd actually be enough light at the right time to image the ice from orbit. It's about a year from now when Phoenix will be in vernal equinox and encasement will be waning.

The Phoenix Project Level 1 requirements state that Level 0 and Level 1 imaging data shall bearchived with PDS within six months of the end of the mission, and all other Level 0 and Level 1data shall be archived within 12 months of the end of the mission [Applicable Document 3]. Theactual delivery schedule will exceed these requirements: the Phoenix Project will make at leasttwo deliveries to the PDS, the first one no later than six months after Sol 30 data are received onEarth, and the second one no later than six months after Sol 90 data are received on Earth. In theevent of an extended mission, subsequent data releases will occur for every 90 sols; for example,Sol 180 plus six months, then Sol 270 plus six months, with the final delivery occurring no laterthan six months after the last data have been received on Earth. Table 5 shows the dates forarchive data acquisition and release.

QUOTE

August 23, 2008 Sol 91: Start of extended missionNovember 20, 2008 Sol 180~ December 9, 2008 Delivery of data from Sols 1 to 30 to PDS two weeks before first release~ December 23, 2008 First data release 6 months after sol 30~ February 8, 2009 Delivery of data from Sols 31 to 90 to PDS two weeks before second release~ February 22, 2009 Second data release 6 months after sol 90TBD Subsequent data releases for every 90 sols through end of mission, with datadelivered to PDS two weeks in advance of release date.

NASA's Phoenix Mars Lander has ceased communications after operating for more than five months. As anticipated, seasonal decline in sunshine at the robot's arctic landing site is not providing enough sunlight for the solar arrays to collect the power necessary to charge batteries that operate the lander's instruments.

Mission engineers last received a signal from the lander on Nov. 2. Phoenix, in addition to shorter daylight, has encountered a dustier sky, more clouds and colder temperatures as the northern Mars summer approaches autumn. The mission exceeded its planned operational life of three months to conduct and return science data.

The project team will be listening carefully during the next few weeks to hear if Phoenix revives and phones home. However, engineers now believe that is unlikely because of the worsening weather conditions on Mars. [...]

Phoenix update: Not dead yet; still in "Lazarus mode;" one attempt at microphone use did not work[...]They attempted to use the MARDI camera, including its microphone, somewhere around sol 146 (give or take a couple sols). It did not respond. But Barry thought that perhaps they hadn't allowed sufficient time for the instrument to warm up before commanding it to take data. Barry said he has "become a true believer in trying to get the microphone on" ever since Veronica McGregor passed him a message that had been received on the Phoenix Twitter feed from a blind man who pointed out that he never had a chance to see the pictures from Mars; sound would allow him, and others like him, to experience a foreign planet for the first time. Barry said he has instructed the team to include an attempt to use the microphone somewhere in the terminal science mode sequence, but he wasn't sure where it fell. [...]

NASA'S Phoenix Mars Lander, with its solar-electric power shrinking due to shorter daylight hours and a dust storm, did not respond to an orbiter's attempt to communicate with it Wednesday night and Thursday morning.

Mission controllers judge the most likely situation to be that declining power has triggered a pre-set precautionary behavior of waking up for only about two hours per day to listen for an orbiter's hailing signal. If that is the case, the wake-sleep cycling would have begun at an unknown time when batteries became depleted.

"We will be coordinating with the orbiter teams to hail Phoenix as often as feasible to catch the time when it can respond," said Phoenix Project Manager Barry Goldstein at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "If we can reestablish communication, we can begin to get the spacecraft back in condition to resume science. In the best case, if weather cooperates, that would take the better part of a week."[...]

The Phoenix mission just issued a statement announcing that, in response to a "low power fault," the spacecraft went into safe mode yesterday. This much was actually expected to happen because of the instructions sent yesterday to the spacecraft to turn off the heater that once kept the robotic arm and TEGA instruments warm. However, the spacecraft evidently surprised mission control by taking more self-protective activities than were anticipated, switching unexpectedly to the "B" side of its electronics. (Like Hubble and indeed most spacecraft, Phoenix basically has two brains, one of them kept unused until and unless its first brain fails. I wish I had that.) It also shut down one of its two batteries.

From the sunlight hours diagram from the last briefing, CO2 encasement begins around February 2, somewhere a little beyond sol 240. But, encasement is probably solid CO2 with no daily break, growing thicker each day.

However, summer will soon turn into the harsh Martian winter and mission management anticipates that the loss of sunlight, extreme arctic cold and accumulation of carbon dioxide frost will prevent operations by December or Jan 2009.

So, maybe we'll see some just before the end. Probably all depends on how long she can last.

The mission will end when the Sun travels low enough in the sky that Phoenix no longer receives sufficient power. The spacecraft will conserve power as long as possible. The cameras will search for the first carbon dioxide frost deposits while the Meteorological Station (MET) instrument monitors the weather conditions.

The northern autumnal equinox will arrive on Mars on December 26, 2008, bringing winter darkness to the north pole. Phoenix will not survive past this date. In fact, it may not survive beyond November.

Do you know which TEGA ovens are full and with which samples? I really want to know the last sample deliveries! are we going to have an ice sample delivery? WHEN? Did they succeed with the WCL-3 try to push the sample into the cell?

I don't think they've announced the results of assisting soil into MECA WCL 3. I'm not sure, but I think the clog is shown before and after in robotic arm images from sol 147 raw images. It shows a mound that appears to to have been mashed. I haven't compared the scenery, or metadata, to see if it's near MECA WCL 3, nor have I examined the image to see parts of the MECA.

My scorecard for used ovens, at the end of September, is above. I'm pretty sure ovens 4, 5, 0, 7, and lately 6 have been announced to be filled.

Oven 3 still appears unopened.

Oven 2 had an organic-free blank delivery attempt during a windy time and probably little to no matter entered; I saw no announcement of success.

Oven 1 had at least 2 icy soil attempts, one missed, one clumped; I saw no announcement of success.

The whole point of the D/H measurement for both the ice table and the atmosphere is to see if they are different, because that would indicate whether the ice table is ancient (possibly from an earlier ocean) or recent (from H2O frost or snow).

I believe they are coming to that conclusion independently of the D/H measurement. From the September 29 briefing, my contemporaneous notes, not a direct quotation, of Peter Smith's opening was:

QUOTE

Ice is connected to ice in atmosphere.

Shows panorama, and notes patterned ground, polygons and troughs, and where ice is under each. Don't see large rocks or dunes. Not much brought in by wind. Nearby: Helmdal Crater, a new crater (just 1 million years). This is not ancient, but new environment. What do we know?

Snow's coming down. Vapor in atmosphere. Vapor can freeze out on ice layer.

I don't recall how they are coming to that conclusion. In the same, was my note:

That's some good news at least. No mention where the soil was from, though. The article also mentions that six of the ovens have been used so far. Therefore there has been one succesful delivery between the last teleconf and this sample acquisition. Likely an OFB sample delivery was finally succesful?

I've followed closely and haven't seen success with OFB sample to oven #2, though I suppose they could be keeping it a secret. My scorecard at the September 29 briefing was:

#4, #5, #0 and #7: used.#1 has had two delivery attempts of icy soil: one missed and one clumped on screen. #2 appears to have since been targeted once for the Organic-Free Blank delivery, but that did not succeed. #6 is barely open. (Now, successfully delivered.)#3 is unopened.

The image on the left is a particle of Martian soil observed with the atomic force microscope on NASA's Phoenix Mars Lander. For comparison, the image on the right is a type of terrestrial material viewed with a scanning electron microscope.

The Mars image covers an area approximately 10 microns wide. The smooth-surfaced, platy particle is consistent with the appearance of phyllosilicate soil. The Martian particle resembles the soil on the left and right perimeter of the terrestrial image.

The terrestrial image shows smectite microboxwork separated from denticulated pyroxene by large pore space. The particles are in a soil sample of saprolitized clinopyroxene from Koua Bocca, Ivory Coast, West Africa. This image's field of view is approximately 23 microns wide.

It says "for comparison" (and not "for contrast") so I take it as: the similarity of the Martian grain to a known Earth phyllosilicate sample, is evidence that the Mars grain is also likely a phyllosilicate. The comparison focuses on the left and right perimeter of the Earth sample.

A high temperature release of water vapor from one of the samples is, Boynton said, “most likely” due to a clay mineral “in the class of minerals called sheet silicates.” While the best known example of a sheet silicate on Earth is mica, in this case on Mars, he said, we're not looking at mica but a different type in which a form of water is actually in the crystal structure between the different sheets.” It’s the water between the sheets that makes the clay minerals “much softer” than mica. The team’s identification of a clay mineral is somewhat ambiguous, he cautioned. “There are a few other minerals that could release water vapor at high temperatures, but we think the sheet silicates or clays are probably most likely.”

During the press conference there may have been mention of that new-release AFM image, so it might be worth digging up a transcript, if it exists. The above source also has:

QUOTE

Bolstering the TEGA evidence for clay minerals, the microscopy instrument on MECA, has turned up hints of a clay-like substance. "We are seeing smooth-surfaced, platy particles with the atomic force microscope, not inconsistent with the appearance of clay particles," Hecht said.

So far, the frost hasn't formed on the lander — except for on the small mirror used to view the wind telltale at the top of the meteorological mast — because Phoenix stays warmer than the ground around it.

"In general the lander itself is designed to absorb as much solar radiation as it can, and to emit relatively little radiation in the infrared. So the lander deck has been much hotter than the surrounding ground surface, for instance," [meteorological team member Peter] Taylor explained. "It's a bit like the top of a relatively warm computer, if you like."

The lander will likely stay warmer than its surroundings for awhile after Phoenix loses the energy it needs to operate, "so it'll be pretty late on when frost actually starts to form on the lander," Taylor said. So Phoenix isn't likely to get any pictures of itself coated in frost.

Right now the frost that is forming is all water ice because it is not yet cold enough at Phoenix's latitude for carbon dioxide ice to form, though it eventually will. Whether the frost will come as a thin coating or a thick sheet, like Mars' polar ice caps, isn't known.

When is the Phoenix team going to deliver the last TEGA sample? 30th September or later? according to their energy levels until when is this possible? Now we should wait the next sample to be from "Upper Cupboard"(ice sample)? in which oven are they going to drop it? are the previous two deliveries, from "Snow White" and OFB successful?

I think they didn't put out news releases about all that so they'd have some things to talk about at the briefing today.

From which trenches do you think the next TEGA samples are going to be? what will they do with the unsuccessful TEGA-1 Snow White sample? they will leave it as it is or they`ll try to fill it with more sample?

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